I am trying to come up with a way to identify the half hour impact from
several exceptions across multiple days. I have access to SQL 2000 and SQL 2005.

The fields that are used would be a start moment ( 9/3/2008 3:45:00 PM),
stop moment (9/3/2008 4:30:00 PM), and total minutes (45). I have hundreds of exceptions with the above data and I need to identify the half hourly impact.

When I have one exception with a start time of 7:15 and an end time of 8:20,
I would like to see the following impacts:

7:00 - .5
7:30 - 1
8:00 - .66

When I have another exception with a start time 7:30 and an end time of 9:15, I would like to see the following impacts:

7:30 – 1
8:00 – 1
8:30 – 1
9:00 - .5

Then when I roll them all up, I would see the following:

7:00 - .5
7:30 – 2
8:00 – 1.66
8:30 – 1
9:00 - .5

What would be the best approach to get these results?

After some thinking (and correction by Pootle), I posted this solution today